The technical principles and implementation of JAX-WS in the Java library are detailed
JAX-WS (Java API for XML Web Services) is a technology in the Java class library to build and develop web services.It is based on Simple Object Access Protocol, which allows developers to pass and exchange data between different applications through networks.
The implementation principles of JAX-WS mainly include the following aspects:
1. WSDL (Web Services Description Language) definition: WSDL is a description document in an XML format to describe the interface and method of web services.JAX-WS understands the structure and method of the service by reading WSDL files.
2. Generate proxy: Using JAX-WS, we can generate clients and server proxy classes according to WSDL files.These proxy classes, as the middle layer between applications and services, hide the bottom -layer SOAP communication details, enabling developers to call the remote method like a local method.
3. Data binding: JAX-WS provides a data binding mechanism to convert XML data in SOAP messages to Java objects.Developers can use annotations or configuration files to specify data binding rules, and map XML elements and attributes to the attributes and methods of Java objects.
4. SOAP communication: JAX-WS uses the SOAP protocol to communicate.The client constructs SOAP messages through the proxy class and sends it to the server.The server obtains the request parameter by parsing the SOAP message, and the response data is encapsulated into the SOAP message to the client.
Below is a simple Java code example using JAX-WS to build a web service:
First, we define an interface as a contract for service:
import javax.jws.WebMethod;
import javax.jws.WebService;
@WebService
public interface HelloService {
@WebMethod
String sayHello(String name);
}
Then, we implement the interface and publish it as a web service:
import javax.jws.WebService;
@WebService(endpointInterface = "com.example.HelloService")
public class HelloServiceImpl implements HelloService {
public String sayHello(String name) {
return "Hello, " + name + "!";
}
public static void main(String[] args) {
Endpoint.publish("http://localhost:8080/hello", new HelloServiceImpl());
}
}
In the above code, we marked the interface and implementation class as a web service through the ``@webService `annotation.`@Webmedhod` Annotation is used to mark the method that can be called external calls.
Finally, we can use the client agent class generated by JAX-WS to call the web service:
import com.example.HelloService;
import com.example.HelloServiceImpl;
public class Client {
public static void main(String[] args) {
HelloService service = new HelloServiceImplService().getHelloServiceImplPort();
String response = service.sayHello("Alice");
System.out.println(response);
}
}
In the above code, `HelloserviceIMPLSERVICE` Class is a client agent generated by JAX-WS based on WSDL files.We can obtain the instance of the server and call the method through this proxy class.
In short, JAX-WS is a technology used in the Java library to build and develop web services.It is defined and generated by WSDL, which realizes SOAP communication and data binding functions, so that developers can easily build and use Web services.
